Water-laid felt



,Patented Feb. 23, 1926.

UNITED. STATES PATENT OFFICE.

HENRY PHILIP-SHOPNECK, OF DORCHESTER, MASSACHUSETTS, ASSIGNOR TO JOHN J.-

DALY, OF WEST NEWTON, MASSACHUSETTS.

WATEE-LAID FELT.

No Drawing.

generally composed of textile rags, or te x-.

tile rags to which has been -added a small percentage of old newspapers or wood pulp.

I The usual method of preparing this sheet,

material consists in beating the rags until the mass has been reduced to a smooth pulp. which is then refined in a jordanning engine, so-called, and which is finally sheeted out by means of a paperm'aking machine.

In order to be capable of running successfully on a papermaking machine. -the fibres of the pulp must of necessity be fairly short--at a maximum approaching 10'millimeters. Such a felt is therefore composed of very short fibres as compared to those found in a woven fabric. f Attempts have been made to prepare paper felt having longer fibres than are usually found in ordinary rag aper' felts.

Such felts would find utility in liolding the stitches of a sewing machine, and in'greatly strengthening a. felt which would later be impregnated with various materials or substances, asasphalt for instance. In all of these attempts the. materialgenerally relied upon to hold the stitches and impart strength to the processed felts, was tannery hair.

In the absence of better felts, "-hair' felts and felts composed of rags and hair have been used. These, however, have been found unsatisfactory for a number of reasons; first, the cost of hair is ver high. being about three times the price 0 common textile rags; second, in the manufacture of asphalt saturated felt, it is necessary to Y sat ate at a high temperature (4( O F.)

. I as t e greater the temperature the quicker the felt will be saturated, due to increased penetration of the saturant, and hence the greater the speed of production. At this temperature and really much below it, hair becomes brittle and may .carbonize and instead of strengthening the felt, either duction.

Application filed November 4, 1925. Serial No. 66,860.

weakens it or makesit very brittle. Third, the incorporation of hair weakens the plain untreated felt. This is due to the fact that hair cannot be reduced to a pulp and felt, in the same sense that rags or wood can, and hence it acts as a long fibrcd ller which reduces the tensile and bursting strength of the felt. Fourth, commercial hair is subject to great variation in pro erties, depending as it does upon the kin of animal, condition of the animal, the season of theyear; climatic conditions, the conditions under which the hair is removed from the animal hide. Hair, therefore, is not constant in physical properties. Fifth, ordinary commercial hair generally carries a considerable percentage of lime-which has become associated with the hair during the depilatoryprocess' The presence of lime is very objectionable due to the fact that it introduces an alkaline substance on the 'pape; machine and hardens the water, and

also because the lime which finds its way into the finished felt makes the felt slightly alkaline, and this greatly retards saturation. Sixth, hair is not an individualized substance as it comes from the animal, and it always lumps up in small wads in the. paper makers' beater. *Since it is desired to keep ulp the fibre long, it is not permissable-to beat the hair hard, and this results in the ne essity of giving the stock a prolonged smooth ing out operation, greatly increasing the time of preparing the stock for the papermaking machine, andhence decreasing pro- Seventh, commercial animal or tannery hair is of limited length by nature. This-operates to disadvantage as it is impossible to obtain very long soft hair averaging 2 inches longf Also, what hair is available varies greatly in length and a genuinely uniform felt with hair cannot be obtained except at prohibitive cost.

My present invention has for its object the preparation of a paper felt which contains long fibres other than hair and which overcomes or surmounts all of the present objectionable features of paper felt containv .ing'hairgand also the preparation of a felt having properties heretofore nonobtainable.

My present invention contemplates the use of, variousvegetable fibres which I have found are capable of being incorporated in paper felt-as long fibres in a felted or unfelted condition. In the reparation of such them. v

The ability to run. an all vegetable fibre felt is peculiar to this class of felt as all hair stock cannot be run on an ordinary paper machine. I may beat out some of the vegetable fibre such as jute, to hydration, and

then add other fibre which has been kept long and run this combined pulp on the paper or. cylinder machine, resulting in an all vegetable fibre felt which is extremely strong. Such vegetable fibres when previously cut to the desired length as on a rag cutter or shredder may be added to the beater along with the rest of the furnish,

and run off on the machine without either lumpingin the beater or clogging the machine, as hair usually does.

As an illustration of the method I prefer to use in manufacturing this felt, I give the following exampleg'the textile rags or other stock, such as wood pulp, newspapers or mixtures of them, are loaded into the heater .and smoothed out to a mere pulp. Theheater roll is raised and the cut upJju-te or other long vegetable fibre is added. Care mustbe taken not to cut the stock with the beater 'roll. After the stock is smoothed out,

it is run off on the paper machine, or if desired, it may be previously passed through a refining engine and then run off on a paper machine to the desired thickness.

Such a felt finds uses to which woven or steam-felted felts are readily put. It may be used to hold'the stitches of a sewing machine, such as when used as a part of an insole in shoes made by the McKay process. It may be saturated with pitch, asphalt or other thermo-plastic binder, and used as a roofing base, flooring base or linoleum backing. When saturated with a thermo-plastic'bind-' er it may be used as a 'box toe material. It is also capable of receiving alcohol or aqueous impregnating solutions without disin .tegrating. In these uses it has a great number of advantages over hair felt, or paper felt containing hair, and the usual temperature of asphalt saturation may be employed, it being as inert as theftextile rags or wood-- pulp with which it is associated. Such a" elt. does not carbonize in the asphalt bath Not having any lime nor become brittle. associated with it it does not make the beater water hard, nor does it cause the felt to be come brittle when it is dried on the paper machine, nor does it decrease the speed ofsaturation in asphalt or pitch. These vegetable fibres only costabout a fourth as much as hair. v

Hair cannot be hydrated in the sense that that term is used to describe the change which ordinary wood pulp undergoes when beaten in the beater in the presence of water. Hair when kept long is inert as far as being capable of'afi'ecting the density of the felt and its hardness. However, vegetable fibre when in the beater may be gradually. slightly hydrated, so as to cause the felt to be come harder and denser and very much stronger. Vegetable fibres when added to the beater do not lump up, but separate generally, being entirely free from the glutinous and calcareous substance so commonly found associated with animal hair.

In producing this felt it is preferable to treat the stock with reference to two features. The shorter the fibre and the longer the hydration, the greater felting effect is attained. On the other. hand, the presence the porosity and softnessof the felt, and increases absorbent power. It istherefore desirable in most instances 'to beat out a certain percentage of fibrous material as a base, as rags, wood pulp, asbestos or suitable mixtures of the same, to a length say of 10 millimeters, .or slightly more or less, and add thereto a suitable portion of long vegetable fibres, i. e. jute having an average length of say an inch or ipch and a half.

A suitable formula is made of rags, 30% jute. capable of practice in great variety and proportions and combinations, and in fact this is one of the great advantages of m felt in that it is capable of being produce with a great variety of characteristics which make it adaptable to a great variety of industries. It is to be understood that what is meant by long vegetable fibres are the elongated fibres composed of a plurality of bundles of fibres which owe their adhesion to the encrusting effect of the ligneous' constituents on the intercellularsubstances.

'All such variants are to be considered as within the purview of'my invention as defined in the appended claims.

of unhydrated long fibres greatly increased As stated above, my invention 18 WhatI therefore claim and desire secure by Letters Patent is '1. A box toe material, consisting of a fibrous pulp and a relatively longer vegetable fibre of the class described distributed throughout the mass in felted relation therewith and impregnated with a thermo-plastic binder.

2. A box toe material, consisting of a fibrous pulp and relatively longer jute fibres distributed throughout the mass'in felted relation therewith and impregnated with a thermo-plastic binder.

3.. A boxtoe material, consisting of a fibrous pulp and relatively longer vegetable fibres of the class described distributed throughout the same in felted relation therewith and impregnated with a thermo-plastic binder, the proportion of Vegetable fibres being substantially less than that of the fibrous pulp.

4. A box toe material, comprising a water-laid felt, consisting of. rag pulp and much longer vegetable fibre dlstributed therethrough and in felted relation therewith, and impregnated with a thermo-plasti binder.

5. A water-laid felt consisting of a rag pulp, and much longer vegetable fibre distributed throughout the mass in felted relation therewith, andcapable of being impregnated with a thermo-plastic binder.

6. A water-laid felt, consisting of a rag pulp and relatively longer ligno-cellulosic fibre of the class described, uniformly distributed therethrough.

In testimony whereof I aflix my signature.

HENRY'PHILIP SHOPNECK. 

